Sprocket-wheel.



J. M. DODGE SPROUKET WHEEL.

APPLICATION FILED NOV. 2a, 1908 Patented. Apr. 12, 1910.

UNITED ATNT FFIQE.

JAMES 1V1. DODGE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR 'IO LINK-BELTCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SPBOCKE'F-VIHEEL.

Specification of Letters Patent.

Patented Apr. 12, 1910.

Application filed November 23, 1908. Serial No. 464,131.

T 0 (ZZZ whom it may concern:

Be it known that I, James M. DODGE, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainimprovements in SprocketWheels, of which the following is aspecification.

My invention relates to certain improvements in sprocket wheels adaptedfor drive chains having teeth which engage the teeth of the wheel.

The object of my invention is to provide flanges for the wheel so as toprevent the chain from slipping off the wheel. This object I attain inthe following manner, ref erence being had to the accompanying drawing,in which Figure l, is a side view showing two sprocket wheels and thedrive chain; Fig. 2, is a sectional view on the line 22, Fig. 1; Fig. 3,is an enlarged side view of a portion of the wheel illustrating myimproved flange; Fig. 4;, is a transverse sectional view on the line ii, Fig. 3; Figs. 5 and 6 are views illustrating modifications of theinvention and Fig. 7, is a view showing rollers mounted on the flangefor taking the wear on the chain.

A, A are two sprocket wheels, in the present instance of differentdiameters, each having teeth a and each sprocket wheel is made identicalwith the other. Adapted to the sprocket wheels is a drive chain made upof links pivoted together and having teeth 5 which mesh with the teethof the sprocket wheels. This is the well known form of silent chain andheretofore the usual practice has been to provide either one or both ofthe wheels with flanges made of flat bands secured to the side of thewheel by bolts or rivets. This band is a permanent fixture and itmaterially increases the cost of the wheel and, as the surface of theband is wide, the side friction of the chain against the flange isconsiderable.

By my invention I reduce the cost of manufacture, provide a simple guardwhich can be readily applied and which will answer the purpose as wellas the ordinary wide flange alluded to above.

I out channels 0 in the face of each tooth near each edge as illustratedin Fig. 4, and preferably taper each end of the tooth at c. The guard ismade in the form of a hoop D; the hoop being preferably made from apiece of round wire, the ends of which are welded together, and thishoop is of a diameter equal to the diameter of the slotted portion 0 ofthe wheel. The hoop is then forced over the ends 0' of the teeth, theinclined surface 0 forming a guide and the metal of the hoop is expandedas pressure is applied so that it will pass over the highest point ofthe portion 0 and spring into the grooves 0 and will be retained inposition by the projecting portion 0 of each tooth. Thus I provide aguard flange which will have the least amount of frictional surface andwhich will retain the chain properly in position on the wheel.

In some instances it may not be necessary to form the projection c oneach tooth as this portion may be cut away from every other tooth, or asmany teeth as desired. There must, however, be a sufficient number ofprojections to hold the flange rigidly in position.

While I have shown in Fig. 1, both the driving and driven wheelsprovided with the flanges, in some instances only one wheel may beprovided with flanges, the other being perfectly plain as heretofore.

The grooves c are usually made of such depth that the upper surface ofthe wire D will be on a line with the ends of the teeth, although thegroove may be made as shown in Fig. 6, in which the wire D will extendbeyond the ends of the teeth, and when it is found necessary,particularly on large size wheels, antifriction rollers (Z may bemounted on the wire flanges between the teeth, as shown in Fig. 7

In place of forcing the wire hoop D over the projections and expandingthe metal of the hoop, the hoop may be made of such diameter that itwill readily pass over the projections and can be shrunk upon the wheelwhen in position, so as to fit snugly in the grooves.

\Vhile I prefer to make the wire hoop round in cross section, it may beof any shape desired. In Fig. 5,1 have shown the wire D with a beveledinner surface cl so that it can be forced over the beveled surface atthe ends of the teeth and engage the corresponding groove in the teethof the wheel.

The hoop D may be made in a single piece having the ends permanentlysecured together as above described, or the ends may be detachablysecured, or the hoop may be made in two or more pieces as fully setforth and claimed in an application for patent filed by me of even dateherewith Serial No. 401,132.

It Will be seen that by making the guard as open at each end thuspreventing the accumulation of dirt on the Wheel.

I claim 1. The combination of a Wheel having teeth on its periphery, theteeth being channeled near each end leaving projections on the teethbeyond the grooves said projections being less in height than the bodyof the teeth, the outer face of the projections shown the space betweenthe teeth is being beveled, and endless hoops mounted in 15 thechannels.

2. The combination of a Wheel having teeth on its periphery, guardsclamped upon the Wheel and resting on the teeth, with antifrictionrollers mounted on the guards be tween the teeth.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing Witnesses.

JAMES M. DODGE. \Vitnesses M. A. BARR,

J 0s. H. KLEIN.

